Method and device for transmitting or receiving multicasting control channel for nb-iot terminal

ABSTRACT

Provided are a method of supporting Single Cell Point-to-Multi-point (SC-PTM) for a Bandwidth reduced Low complexity/Coverage Enhancement (BL/CE) terminal or an NB-IoT terminal, which are for a Machine Type Communication (MTC) application defined in a 3 GPP LTE/LTE-A system. The method may include receiving configuration information relating to an NPDCCH search space from a base station wherein the NPDCCH search space is separately configured to receive scheduling control information for the multicasting control channel; receiving the scheduling control information for the multicasting control channel through the NPDCCH search space configured based on the to configuration information; and receiving the multicasting control channel based on the scheduling control information, wherein the configuration information is received through higher layer signaling.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority from Korean Patent Application Nos.10-2016-0103189 & 10-2017-0081319, filed on Aug. 12, 2016 & Jun. 27,2017, which are hereby incorporated by reference for all purposes as iffully set forth herein.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present embodiments relate to a method of supporting a Single CellPoint-to-Multipoint (SC-PTM) for an narrow band Internet of Thing(NB-IoT)terminal defined in a third generation group projectparthnership (3GPP) long term evolution (LTE)/LTE-Advanced system.

2. Description of the Prior Art

In 3GPP Release-12/13, a Bandwidth Reduced Low complexity (BL) terminaltechnology and a Coverage Enhancement (CE) terminal technology have beenstandardized. A Low Complexity (LC) terminal represents a terminaltargetting low-end application having a low profit, a low speed, and alow latency sensitivity, such as some Machine Type Communication (MTC)terminals. The LC terminal has reduced Tx and Rx capabilities comparedto terminals of other categories. A BL terminal operates in an LTEsystem band having a limited channel bandwidth of 6PRB corresponding toa maximum channel bandwidth available in a 1.4 MHz LTE system. A CEterminal needs an enhanced coverage function to connect to a cell.

In 3GPP Release-13, Narrowband Internet of Things (NB-IoT) technologyhas been standardized. The aspect thereof is to specify a wirelessaccess for cellular IoT, and includes improved indoor coverage, supportfor large-scale low-speed terminals, low latency sensitivity, very lowcost of terminals, low power consumption, and optimized networkarchitecture.

In Release-13, a BL/CE terminal or an NB-IoT terminal has been providedwith functions for enabling the 3GPP system to rapidly penetrate into alow-cost IoT market. Accordingly, some functions provided to a typicalLTE terminal that provides a mobile broadband service are not providedto the BL/CE terminal or the NB-IoT terminal.

For example, multicast transmission (an MBMS service or SC-PTMtransmission) provided to a typical LTE terminal is not provided to aRelease-13 BL/CE terminal or a Release-13 NB-IoT terminal. Therefore,there is no method defined for supporting multicast transmission of aBL/CE terminal or an NB-IoT terminal in Release-13.

SUMMARY OF THE INVENTION

An aspect of the present embodiments is to provide a method ofconfiguring a search space of a downlink control channel capable ofsupporting multicasting control channel transmission for an NB-IoTterminal.

In an aspect, the present embodiments provide a method of receiving amulticasting control channel (SC-MCCH) by a NarrowBand-Internet ofThings (NB-IoT) terminal, the method including: receiving configurationinformation relating to an NPDCCH search space from a base stataoin,wherein the NPDCCH search space is separately configured to receivescheduling control information for the multicasting control channel;receiving the scheduling control information for the multicastingcontrol channel through the NPDCCH search space configured based on theconfiguration information; and receiving the multicasting controlchannel based on the scheduling control information, in which theconfiguration information is received through higher layer signaling.

In another aspect, the present embodiments provide a method oftransmitting a multicasting control channel for an NB-IoT terminal, themethod including: configuring a separate NPDCCH search space fortransmitting scheduling control information for the multicasting controlchannel; transmitting the scheduling control information for themulticasting control channel through the NPDCCH search space; andtransmitting the multicasting control channel based on the schedulingcontrol information, in which configuration information relating to theNPDCCH search space is transmitted through higher layer signaling.

In still another aspect, the present embodiments provide an NB-IoTterminal that receives a multicasting control channel, the NB-IoTterminal including: a reception unit that receives configurationinformation relating to an NPDCCH search space from a base stataion,wherein the NPDCCH search space is separately configured to receivescheduling control information for the multicasting control channel; anda control unit that checks the scheduling control information for themulticasting control channel through the NPDCCH search space configuredbased on the configuration information, and controls reception of themulticasting control channel based on the scheduling controlinformation, in which the configuration information is received throughhigher layer signaling.

In still another aspect, the present embodiments provide a base stationthat transmits a multicasting control channel for an NB-IoT terminal,the base station including: a control unit that configures a separateNPDCCH search space for transmitting scheduling control information forthe multicasting control channel, and controls transmission of thescheduling control information for the multicasting control channelthrough the NPDCCH search space; and a transmission unit that transmitsthe multicasting control channel based on the scheduling controlinformation, in which configuration information relating to the NPDCCHsearch space is transmitted through higher layer signaling.

According to the present embodiments, it is possible to supportmulticasting control channel transmission for an NB-IoT terminal byconfiguring a separate downlink control channel search space fortransmitting or receiving scheduling control information for amulticasting control channel.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the presentdisclosure will be more apparent from the following detailed descriptiontaken in conjunction with the accompanying drawings, in which:

FIG. 1 and FIG. 2 are diagrams illustrating a system information blockin which a base station broadcasts information for enabling a terminalto receive SC-MCCH information;

FIG. 3 is a diagram illustrating a PDCCH and a PDSCH, configured by aG-RNTI or an SC-RNTI, in relation to a search space of a terminal towhich SC-PTM is applied;

FIG. 4 is a diagram illustrating a PDCCH configured by an SC-N-RNTI inrelation to search space of a terminal to which SC-PTM is applied;

FIG. 5 to FIG. 8 are diagrams illustrating an MPDCCH candidate monitoredby a BL/CE terminal in relation to an MPDCCH search space;

FIG. 9 is a diagram illustrating determination of a repetition level inrelation to an MPDCCH search space;

FIG. 10 is a diagram illustrating a repetition level for a Type1-MPDCCHcommon search space in relation to an MPDCCH search space;

FIG. 11 is a diagram illustrating mapping for a DCI subframe repetitionnumber in relation to an MPDCCH search space;

FIG. 12 is a diagram illustrating an NPDCCH terminal-specific searchspace candidate in relation to an NPDCCH search space;

FIG. 13 is a diagram illustrating a Type1-NPDCCH common search spacecandidate in relation to an NPDCCH search space;

FIG. 14 is a diagram illustrating a Type2-NPDCCH common search spacecandidate in relation to an NPDCCH search space;

FIG. 15 and FIG. 16 are diagrams illustrating a method of transmittingor receiving a multicasting control channel for an NB-IoT terminal;

FIG. 17 and FIG. 18 are diagrams illustrating a method for transmittingor receiving a multicasting control channel for a BL/CE terminal;

FIG. 19 is a diagram illustrating a user equipment according to anembodiment; and

FIG. 20 is a diagram illustrating a base station according to anembodiment.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Hereinafter, embodiments of the present disclosure will be described indetail with reference to the accompanying drawings. In adding referencenumerals to elements in each drawing, the same elements will bedesignated by the same reference numerals, if possible, although theyare shown in different drawings. Further, in the following descriptionof the present disclosure, a detailed description of known functions andconfigurations incorporated herein will be omitted when it is determinedthat the description may make the subject matter of the presentdisclosure rather unclear.

In the present specification, an MTC terminal may refer to a terminalsupporting low cost (or low complexity), a terminal supporting coverageenhancement, or the like. In the present specification, an MTC terminalmay refer to a terminal supporting low cost (or low complexity),coverage enhancement, and the like. Alternatively, in the presentspecification, an MTC terminal refers to a terminal that is defined tobe in a predetermined category for supporting low costs (or lowcomplexity) and/or coverage enhancement.

In other words, in the present specification, an MTC terminal may referto a newly defined 3GPP Release-13 low cost (or low complexity) UEcategory/type, which performs LTE-based MTC related operations.Alternatively, in the present specification, the MTC terminal may referto a UE category/type that is defined in or before 3GPP Release-12 thatsupports the enhanced coverage in comparison with the existing LTEcoverage, or supports low power consumption, or may refer to a newlydefined Release-13 low cost (or low complexity) UE category/type.

The wireless communication system of the present disclosure may bewidely installed so as to provide various communication services, suchas a voice service, packet data, and the like. The wirelesscommunication system may include a User Equipment (UE) and a BaseStation (BS or an eNB). Throughout the specification, the user equipmentmay be an inclusive concept indicating a user terminal utilized inwireless communication, including a User Equipment (UE) in WCDMA, LTE,HSPA, and the like, and a Mobile station (MS), a User Terminal (UT), aSubscriber Station (SS), a wireless device, and the like in GSM.

A base station or a cell may generally refer to a station wherecommunication with a user equipment is performed, and may also bereferred to as other terms including a Node-B, an evolved Node-B (eNB),a Sector, a Site, a Base Transceiver System (BTS), an Access Point, aRelay Node, a Remote Radio Head (RRH), a Radio Unit (RU), a small cell,and the like.

That is, in the present specification, the base station or the cell maybe construed as an inclusive concept indicating a function or a portionof an area covered by a Base Station Controller (BSC) in CDMA, a NodeBin WCDMA, an eNB or a sector (site) in LTE, and the like, and theconcept may include various coverage areas, such as a megacell, amacrocell, a microcell, a picocell, a femtocell, and communicationranges of a relay node, an RRH, an RU, a small cell, and the like.

Each of the above mentioned various cells has a base station thatcontrols a corresponding cell, and thus, the base station may beconstrued in two ways: i) the base station may be a device itself thatprovides a megacell, a macrocell, a microcell, a picocell, a femtocell,and a small cell in association with a wireless area; or ii) the basestation may indicate a wireless area itself. In i), all devices thatinteract with one another so as to enable the devices that provide apredetermined wireless area to be controlled by an identical entity orto cooperatively configure the wireless area, may be indicated as a basestation. Based on a configuration type of a wireless area, an eNB, anRRH, an antenna, an RU, a Low Power Node (LPN), a point, a transmissionor reception point, a transmission point, a reception point, and thelike may be embodiments of a base station. In ii), a wireless areaitself that receives or transmits a signal from a perspective of a userequipment or a neighboring base station, may be indicated as a basestation.

Therefore, a megacell, a macrocell, a microcell, a picocell, afemtocell, a small cell, an RRH, an antenna, an RU, an LPN, a point, aneNB, a transmission or reception point, a transmission point, and areception point are commonly referred to as a base station.

In the present specification, a user equipment and a base station areused as two inclusive transceiving subjects to embody the technology andtechnical concepts described in the specification, and may not belimited to a predetermined term or word. In the specification, a userequipment and a base station are used as two (uplink or downlink)inclusive transceiving subjects to embody the technology and technicalconcepts described in the specification, and may not be limited to apredetermined term or word. Here, Uplink (UL) refers to a scheme for aUE to transmit data to or receive data from a base station, and Downlink(DL) refers to a scheme for a base station to transmit data to andreceive data from a UE.

Various multiple access schemes may be unrestrictedly applied to thewireless communication system. Various multiple access schemes, such asCode Division Multiple Access (CDMA), Time Division Multiple Access(TDMA), Frequency Division Multiple Access (FDMA), Orthogonal FrequencyDivision Multiple Access (OFDMA), OFDM-FDMA, OFDM-TDMA, OFDM-CDMA, andthe like may be used. An embodiment of the present disclosure may beapplicable to resource allocation in an asynchronous wirelesscommunication scheme that is advanced through GSM, WCDMA, and HSPA, tobe LTE and LTE-advanced, and may be applicable to resource allocation ina synchronous wireless communication scheme that is advanced throughCDMA and CDMA-2000, to be UMB. The present disclosure may not be limitedto a specific wireless communication field, and may include alltechnical fields in which the technical idea of the present disclosureis applicable.

Uplink transmission and downlink transmission may be performed based ona Time Division Duplex (TDD) scheme that performs transmission based ondifferent times, or based on a Frequency Division Duplex (FDD) schemethat performs transmission based on different frequencies.

Further, in a system such as LTE and LTE-A, a standard may be developedby configuring an uplink and a downlink based on a single carrier or apair of carriers. The uplink and the downlink may transmit controlinformation through a control channel, such as a Physical DownlinkControl Channel (PDCCH), a Physical Control Format Indicator Channel(PCFICH), a Physical Hybrid ARQ Indicator Channel (PHICH), a PhysicalUplink Control Channel (PUCCH), an Enhanced Physical Downlink ControlChannel (EPDCCH), and the like, and may be configured as a data channel,such as a Physical Downlink Shared Channel (PDSCH), a Physical UplinkShared Channel (PUSCH), and the like, so as to transmit data.

Control information may be transmitted using an enhanced PDCCH orextended PDCCH (EPDCCH).

In the present specification, a cell may refer to the coverage of asignal transmitted from a transceiving point, a component carrier havingthe coverage of the signal transmitted from the transceiving point(transmission point, or transmission or reception point), or thetransceiving point itself.

A wireless communication system, according to embodiments, refers to aCoordinated Multi-point transmission or reception (CoMP) system wheretwo or more transmission or reception points cooperatively transmit asignal, a coordinated multi-antenna transmission system, or acoordinated multi-cell communication system. A CoMP system may includeat least two multi-transmission or reception points and terminals.

A multi-transmission or reception point may be a base station or a macrocell (hereinafter, referred to as an “eNB”) and at least one RRH that isconnected to the eNB through an optical cable or an optical fiber and iswirely controlled, and has a high transmission power or a lowtransmission power within a macro cell area.

Hereinafter, a downlink refers to communication or a communication pathfrom a multi-transmission or reception point to a terminal, and anuplink refers to communication or a communication path from a terminalto a multi-transmission or reception point. In a downlink, a transmittermay be a part of a multiple transmission or reception point and areceiver may be a part of a terminal. In an uplink, a transmitter may bea part of a terminal and a receiver may be a part of a multipletransmission or reception point.

Hereinafter, the situation in which a signal is transmitted or receivedthrough a PUCCH, a PUSCH, a PDCCH, an EPDCCH, a PDSCH, or the like maybe described through the expression, “a PUCCH, a PUSCH, a PDCCH, anEPDCCH, or a PDSCH is transmitted or received”.

In addition, hereinafter, the expression “a PDCCH is transmitted orreceived, or a signal is transmitted or received through a PDCCH”includes “an EPDCCH is transmitted or received, or a signal istransmitted or received through an EPDCCH”.

That is, a physical downlink control channel used herein may indicate aPDCCH or an EPDCCH, and may indicate a meaning including both a PDCCHand an EPDCCH.

In addition, for ease of description, an EPDCCH, which corresponds to anembodiment of the present disclosure, may be applied to the partdescribed using a PDCCH and to the part described using an EPDCCH.

Meanwhile, higher layer signaling includes an radio resource control(RRC) signaling that transmits RRC information including an RRCparameter.

An eNB performs downlink transmission to terminals. The eNB may transmita Physical Downlink Shared Channel (PDSCH) which is a primary physicalchannel for unicast transmission. The eNB may transmit a PhysicalDownlink Control Channel (PDCCH) for transmitting downlink controlinformation, such as scheduling required for reception of a PDSCH, andscheduling grant information for transmission of an uplink data channel(for example, a Physical Uplink Shared Channel (PUSCH)). Hereinafter,transmission or reception of a signal through each channel will bedescribed as transmission or reception of a corresponding channel.

In 3GPP Release-12/13, a Bandwidth Reduced Low complexity (BL) terminaltechnology and a Coverage Enhancement (CE) terminal technology have beenstandardized. A Low Complexity (LC) terminal represents a terminaltargeting low-end application having a low profit, a low speed, and alow latency sensitivity, such as some Machine Type Communication (MTC)terminals. The LC terminal has reduced Tx and

Rx capabilities compared to terminals of other categories. A BL terminaloperates in an LTE system band having a limited channel bandwidth of6PRB corresponding to a maximum channel bandwidth available in a 1.4 MHzLTE system. A CE terminal needs an enhanced coverage function to connectto a cell.

In 3GPP Release-13, Narrowband Internet of Things (NB-IoT) technologyhas been standardized. The aspect thereof is to specify a wirelessaccess for cellular IoT, and includes improved indoor coverage, supportfor large-scale low-speed terminals, low latency sensitivity, very lowcost of terminals, low power consumption, and optimized networkarchitecture.

In Release-13, a BL/CE terminal or an NB-IoT terminal has been providedwith functions for enabling the 3GPP system to rapidly penetrate into alow-cost IoT market. Accordingly, some functions provided to a generalLTE terminal that provides a mobile broadband service are not providedto the BL/CE terminal or the NB-IoT terminal. For example, multicasttransmission (an MBMS service or SC-PTM transmission) provided to ageneral LTE terminal is not provided to an Release-13 BL/CE terminal oran Release-13 NB-IoT terminal. Hereinafter, descriptions will beprovided based on SC-PTM for ease of description, but MBSFN transmissionis also included in the scope of the present disclosure.

In LTE, MBMS transmission uses one of MBSFN transmission and SC-PTMtransmission. MCE determines whether to use SC-PTM or MBSFN for eachMBMS session. SC-PTM corresponds to MBMS transmission in a single-cellcoverage. In SC-PTM, an SC-MCCH, i.e., a control channel, andSC-MTCH(s), i.e., one or more traffic channels, are provided. TheSC-MCCH, i.e., a control channel and the SC-MTCH(s), i.e., one or moretraffic channels are mapped on a DL-SCH (i.e., a PDSCH).

According to the related art, a terminal can identify SC-MCCHtransmission on a PDCCH by using an SC-RNTI. Here, the SC-MCCH indicatesa control channel for transmitting control information associated withMBMS transmission by using SC-PTM or the control information. TheSC-MCCH uses a modification period. A notification mechanism is used toannounce a change of the SC-MCCH due to a start of a session. Thenotification is transmitted within a first sub-frame in a repetitionperiod in which the SC-MCCH may be scheduled. The notification istransmitted using a DCI format 1C with a Single Cell Notification RNTI(SC-N-RNTI) and one bit within an 8-bit bitmap. When the terminalreceives the notification, the SC-MCCH is acquired in the same subframe.The terminal detects a change of the SC-MCCH, which is not announced bythe notification mechanism, through SC-MCCH monitoring in themodification period.

[SC-PTM]

A terminal configured with an MBMS service through an SC-MRB may acquiretiming information for SC-MCCH information acquisition throughSystemInformationBlockType20 (SIB20).

According to the related art, a terminal searches for a common searchspace on a PDCCH by using a Single Cell RNTI (SC-RNTI). Thus, theterminal receives PDSCH resource allocation information for SC-MCCHtransmission and receives SC-MCCH information through a correspondingPDSCH based on the received PDSCH resource allocation information. Abase station broadcasts information for enabling the terminal to receivethe SC-MCCH information through the SIB20. Information included in theSIB20 includes sc-mcch-RepetitionPeriod information defining an intervalbetween SC-MCCH information transmissions, sc-mcch-Offset indicating aradio frame in which the SC-MCCH is scheduled, sc-mcch-FirstSubframeinformation indicating a first subframe in which the SC-MCCH isscheduled, and sc-mcch-duration information indicating a duration inwhich the SC-MCCH may be scheduled starting from the subframe indicatedby sc-mcch-FirstSubframe. A detailed definition of this will be providedin the following excerpts from TS36.331.

TS36.331

SystemInformationBlockType20

The IE SystemInformationBlockType20 illustrated in FIG. 1 and FIG. 2contains the information required to acquire the control informationassociated transmission of MBMS using SC-PTM.

[Search Space for SC-PTM]

As described above, control information (SC-MCCH) and data information(SC-MTCH) for a terminal to which the SC-PTM is applied are individuallytransmitted through a PDSCH, and corresponding PDSCH resource allocationinformation is individually transmitted through a common search space ofa PDCCH, in which the control information (SC-MCCH) is CRC-scrambled byan SC-RNTI and transmitted, and the data information (SC-MTCH) isCRC-scrambled by a G-RNTI and transmitted. Further, changenotification-related bitmap information for notifying of a change of theSC-MCCH is CRC-scrambled by an SC-N-RNTI and transmitted through a PDCCHcommon search space.

In this regard, detailed descriptions associated with a terminal searchspace for SC-PTM and related DCI format configuration will be providedin the following excerpts from TS36.213.

TS36.213 If a UE is configured by higher layers to decode PDCCH with CRCscrambled by the G-RNTI or SC-RNTI, the UE shall decode the PDCCH andthe corresponding PDSCH according to any of the combinations defined inTable 7.1-4 in FIG. 3. The scrambling initialization of PDSCHcorresponding to these PDCCHs is by G-RNTI or SC-RNTI.

If a UE is configured by higher layers to decode PDCCH with CRCscrambled by the SC-N-RNTI, the UE shall decode the PDCCH according tothe combination defined in table 7.1-4A in FIG. 4.

[MPDCCH Search Space Configuration]

Four search spaces are defined as MPDCCH search spaces for a Rel-13BL/CE terminal. A type-0 common search space is defined to performmonitoring only when the terminal is configured with CEModeA. A type-1common search space is defined for paging, a type-2 common search spaceis defined for a random access procedure, and a UE-specific search spaceis defined for UE-specific data transmission or reception

Detailed descriptions associated with the MPDCCH search spaceconfiguration will be provided in the following excerpts from TS36.213.

TS36.213

9.1.5 MPDCCH Assignment Procedure

A BL/CE UE shall monitor a set of MPDCCH candidates on one or moreNarrowbands (described in subclause 5.2.4 of [3]) as configured byhigher layer signalling for control information, where monitoringimplies attempting to decode each of the MPDCCHs in the set according toall the monitored DCI formats. The Narrowband in a subframe used forMPDCCH monitoring is determined as described in [3].

A UE that is not a BL/CE UE is not required to monitor MPDCCH.

Higher layer signalling can configure a BL/CE UE with one or twoMPDCCH-PRB-sets for MPDCCH monitoring. The PRB-pairs corresponding to anMPDCCH-PRB-set are indicated by higher layers. Each MPDCCH-PRB-setconsists of set of ECCEs numbered from 0 to N′_(ECCE,p,k)−1 whereN′_(ECCE,p,k) is the number of ECCEs in MPDCCH-PRB-set p of subframe k.The MPDCCH-PRB-set(s) can be configured by higher layers for eitherlocalized MPDCCH transmission or distributed MPDCCH transmission. Theset of MPDCCH candidates to monitor are defined in terms of MPDCCHsearch spaces. The BL/CE UE shall monitor one or more of the followingsearch spaces

-   -   a Type0-MPDCCH common search space if configured with CEmodeA,    -   a Type1-MPDCCH common search space,    -   a Type2-MPDCCH common search space, and    -   a MPDCCH UE-specific search space.

A BL/CE UE configured with CEModeB is not required to monitorType0-MPDCCH common search space.

The BL/CE UE is not required to simultaneously monitor MPDCCHUE-specific search space and Type1-MPDCCH common search space.

The BL/CE UE is not required to simultaneously monitor MPDCCHUE-specific search space and Type2-MPDCCH common search space.

A BL/CE UE is not expected to monitor an MPDCCH candidate, if an ECCEcorresponding to that MPDCCH candidate is mapped to a PRB pair thatoverlaps with a transmission of PDSCH scheduled previously in the samesubframe. For aggregation level L′=24 or L′=12 ECCEs, the number ofECCEs refers to the MPDCCH mapping to the REs of the 2+4 PRB set asdefined in [3]. An MPDCCH search space MS_(k) ^((L′,R)) at aggregationlevel L′∈{1,2,4,8,16,12,24} and repetition levelR∈{1,2,4,8,16,32,64,128,256} is defined by a set of MPDCCH candidateswhere each candidate is repeated in a set of R consecutive BL/CEdownlink subframes starting with subframe k. For an MPDCCH-PRB-set p,the ECCEs corresponding to MPDCCH candidate m of the search space MS_(k)^((L′,R)) are given by

$\begin{matrix}{\mspace{79mu} {{{L\left\{ {\left( {Y_{p,k} + \left\lfloor \frac{{m \cdot N}\text{?}}{L \cdot M_{p}^{\prime {(L^{\prime})}}} \right\rfloor} \right){mod}\left\lfloor {N\text{?}} \right\rfloor} \right\}} + i}\mspace{79mu} {{{{where}\mspace{14mu} t} = 0},\ldots \mspace{14mu},{L^{\prime} - 1}}\mspace{79mu} {{m = 0},1,\ldots \mspace{14mu},{M_{p}^{\prime {(L^{\prime})}} - 1}}{\text{?}\text{indicates text missing or illegible when filed}}}} & \;\end{matrix}$

M′_(p) ^((L′)) is the number of MPDCCH candidates to monitor ataggregation level L′ in MPDCCH-PRB-set p in each subframe in the set ofR consecutive subframes.

Y_(p,k) for MPDCCH UE-specific search space is determined as describedin subclause 9.1.4, and Y_(p,k)=0 for Type0-MPDCCH common search space,Type1-MPDCCH common search space and Type2-MPDCCH common search space.

A BL/CE UE is not expected to monitor MPDCCH in subframes that are notBL/CE DL subframes.

Until BL/CE UE receives higher layer configuration of MPDCCH UE-specificsearch space, the BL/CE UE monitors MPDCCH according to the sameconfiguration of MPDCCH search space and Narrowband as that for MPDCCHscheduling Msg4.

The aggregation and repetition levels defining the MPDCCH search spacesand the number of monitored MPDCCH candidates are given as follows:

For MPDCCH UE-specific search space

-   -   if the BL/CE UE is configured with N′_(RB) ^(X) ^(p) or N′_(RB)        ^(X) ^(p) =4 PRB-pairs, and mPDCCH-NumRepetition=1, and    -   if the MPDCCH-PRB-set is configured for distributed        transmission, the aggregation levels defining the search spaces        and the number of monitored MPDCCH candidates are listed in        Table 9.1.4-1a and Table 9.1.4-1b, where L is substituted with        L′ for L≤24, and N′_(RB) ^(X) ^(p) is substituted with N′_(RB)        ^(X) ^(p) .    -   if the MPDCCH-PRB-set is configured for localized transmission,        the aggregation levels defining the search spaces and the number        of monitored MPDCCH candidates are listed in Table 9.1.4-2a and        Table 9.1.4-2b, where L is substituted with L′ and N′_(RB) ^(X)        ^(p) substituted with N′_(RB) ^(X) ^(p) .    -   otherwise    -   if the UE is configured with CEModeA, and N′_(RB) ^(X) ^(p) =2        or N′_(RB) ^(X) ^(p) =4, the aggregation and repetition levels        defining the search spaces and the number of monitored MPDCCH        candidates are listed in Table 9.1.5-1a in FIG. 5    -   if the UE is configured with CEModeA, and N′_(RB) ^(X) ^(p)        =2+4, the aggregation and repetition levels defining the search        spaces and the number of monitored MPDCCH candidates are listed        in Table 9.1.5-1b in FIG. 6    -   if the UE is configured with CEModeB, and N′_(RB) ^(X) ^(p) =2        or N′_(RB) ^(X) ^(p) =4 the aggregation and repetition levels        defining the search spaces and the number of monitored MPDCCH        candidates are listed in Table 9.1.5-2a in FIG. 7    -   if the UE is configured with CEModeB, and N′_(RB) ^(X) ^(p)        =2+4, the aggregation and repetition levels defining the search        spaces and the number of monitored MPDCCH candidates are listed        in Table 9.1.5-2b in FIG. 8    -   N′_(RB) ^(X) ^(p) is the number of PRB-pairs configured for        MPDCCH UE-specific search space. When N′_(RB) ^(X) ^(p) =2+4 it        is given by the higher layer parameter numberPRB-Pairs-r13, and        when N′_(RB) ^(X) ^(p) =2 or N′_(RB) ^(X) ^(p) =4, it is given        by the higher layer parameter numberPRB-Pairs-r11.

r1,r2,r3,r4 are determined from Table 9.1.5-3 in FIG. 9 by substitutingthe value of r_(max) with the value of higher layer parametermPDCCH-NumRepetthon.

The PRB-pairs within a Narrowband corresponding to an MPDCCH-PRB-set areindicated by higher layers and are determined using the descriptiongiven in subclause 9.1.4.4.

If higher layer configuration numberPRB-Pairs-r13 for MPDCCH-PRB-set pis 6, N′_(RB) ^(X) ^(p) =2+4 and the number of PRB-pairs in anMPDCCH-PRB-set p=2+4.

If Type2-MPDCCH common search space,

-   -   PRB-pairs of the 2 PRB set in the 2+4 PRB set correspond to        PRB-pairs with the largest two PRB indices in MPDCCH-PRB-set p.    -   PRB-pairs of the 4 PRB set in the 2+4 PRB set correspond to        PRB-pairs with the smallest 4 PRB indices in MPDCCH-PRB-set p.    -   PRB-pairs of the 2+4 PRB set in the 2+4 PRB set correspond to        all PRB-pairs in MPDCCH-PRB-set p.

For Type0-MPDCCH common search space, the narrowband location and theMPDCCH-PRB-set p are the same as for MPDCCH UE-specific search space,and

-   -   if N′_(RB) ^(X) ^(p) =2    -   M′_(p) ^((L′))=1 for L′=8 and repetition levels r1,r2,r3,r4        given in Table 9.1.5.-3. For all other cases, M′_(p) ^((L′))=0    -   if N′_(RB) ^(X) ^(p) =4    -   M′_(p) ^((L′))=1 for L′=16 and repetition levels r1,r2,r3,r4        given in Table 9.1.5.-3. For all other cases, M′_(p) ^((L′))=0    -   if N′_(RB) ^(X) ^(p) =2+4    -   M′_(p) ^((L′))=1 for L′=24 and repetition levels r1,r2,r3,r4        given in Table 9.1.5.-3. For all other cases, M′_(p) ^((L′))=0

For Type1-MPDCCH common search space, the number of PRB-pairs inMPDCCH-PRB-set p is 2+4 PRB-pairs, and

-   -   M′_(p) ^((L′))=1 for L′=24 and repetition levels r1,r2,r3,r4        where the repetition levels are determined from Table 9.1.5-4 in        FIG. 10 by substituting the value of r_(max) with higher layer        parameter mPDCCH-NumRepetition-Paging.    -   For all other cases, M′_(p) ^((L′))=0

For Type2-MPDCCH common search space, the number of PRB-pairs inMPDCCH-PRB-set p is 2+4 PRB-pairs, and

-   -   If the most recent coverage enhancement level used for PRACH is        coverage enhancement level 0 and 1, the aggregation and        repetition levels defining the search spaces and the number of        monitored MPDCCH candidates are determined from Table 9.1.5-1b,        by assuming that the number of candidates for <8 as zero.    -   If the most recent coverage enhancement level used for PRACH is        coverage enhancement level 2 and 3, the aggregation and        repetition levels defining the search spaces and the number of        monitored MPDCCH candidates are determined from Table to        9.1.5-2b.

where r1,r2,r3,r4 are determined from Table 9.1.5-3 by substituting thevalue of r_(max) with the value of higher layer parametermPDCCH-NumRepetition-RA.

In tables 9.1.5-1a, 9.1.5-1b, 9.1.5-2a, 9.1.5-2b, and for Type0, Type1,Type2 MPDCCH common search space, L′ is applied for N_(EREG) ^(ECCE)=4,and L″ is applied for N_(EREG) ^(ECCE)=8 wherein L″=L′/2 substitutingthe values of L′.

For Type1-MPDCCH common search space and Type2-MPDCCH common searchspace, distributed MPDCCH transmission is used.

For MPDCCH UE-specific search space, Type0-common search space, andType2-common search space locations of starting subframe k are given byk=k_(D) where k_(b) is the b^(th) consecutive BL/CE DL subframe fromsubframe k₀, and b=u·rj, and

${u = 0},1,\ldots \mspace{14mu},{\frac{r_{\max}}{rt} - 1},$

and j∈{1,2,3,4} where

-   -   subframe k0 is a subframe satisfying the condition        (10n_(f)+└n_(s)/Z┘)mod T=0 where T=r_(max)·G    -   For MPDCCH UE-specific search space, Type0-common search space        is G given by the higher layer parameter mPDCCH-startSF-UESS,    -   For Type2-common search space, G is given by the higher layer        parameter mPDCCH-startSF-CSS-RA-r13    -   r_(max) is given by higher layer parameter mPDCCH-NumRepetition,        and    -   r1,r2,r3,r4 are given in Table 9.1.5-3.

A BL/CE UE is not expected to be configured with values of r_(max) and Gthat result in non-integer values of T.

For Type1-common search space, k=k0 and is determined from locations ofpaging opportunity subframes,

If SystemInformationBlockType1-BR or SI message is transmitted in onenarrowband in subframe k, a BL/CE UE shall assume MPDCCH in the samenarrowband in the subframe k is dropped.

The BL/CE UE is not required to monitor an MPDCCH search space if anyECCEs corresponding to any of its MPDCCH candidates occur within a framebefore n_(f)=0 and also occur within frame n_(f)=0.

For MPDCCH UE-specific search space or for Type0-common search space ifthe higher layer parameter mPDCCH-NumRepetition is set to 1; or forType2-common search space if the higher layer parametermPDCCH-NumRepetition-RA is set to 1;

-   -   The BL/CE UE is not required to monitor MPDCCH    -   For TDD and normal downlink CP, in special subframes for the        special subframe configurations 0 and 5 shown in Table 4.2-1 of        [3]    -   For TDD and extended downlink CP, in special subframes for the        special subframe configurations 0, 4 and 7 shown in Table 4.2-1        of [3];

Otherwise

-   -   The BL/CE UE is not required to monitor MPDCCH    -   For TDD, in special subframes, if the BL/CE UE is configured        with CEModeB    -   For TDD and normal downlink CP, in special subframes for the        special subframe configurations 0, 1, 2,5,6,7 and 9 shown in        Table 4.2-1 of [3], if the BL/CE UE is configured with CEModeA    -   For TDD and extended downlink CP, in special subframes for the        special subframe configurations 0, 4, 7, 8 and 9 shown in Table        4.2-1 of [3], if the BL/CE UE is configured with CEModeA.

The number of MPDCCH repetitions is indicated in the ‘DCI subframerepetition number’ field in the DCI according to the mapping in Table9.1.5-5 in FIG. 11.

[NPDCCH Search Space Configuration]

Three search spaces are defined as NPDCCH search spaces for a Rel-13NB-IoT terminal. A type-1 common search space is defined for paging, atype-2 common search space is defined for a random access procedure, anda UE-specific search space is defined for UE-specific data transmissionor reception.

Detailed descriptions associated with NPDCCH search space configurationwill be provided in the following excerpts from TS36.213.

TS36.213

16.6 Narrowband Physical Downlink Control Channel Related Procedures

A UE shall monitor a set of NPDCCH candidates (described in subclause10.2.2.1 of [3]) as configured by higher layer signalling for controlinformation, where monitoring implies attempting to decode each of theNPDCCHs in the set according to all the monitored DCI formats.

The set of NPDCCH candidates to monitor are defined in terms of NPDCCHsearch spaces.

The UE shall monitor one or more of the following search spaces

-   -   a Type1-NPDCCH common search space,    -   a Type2-NPDCCH common search space, and    -   a NPDCCH UE-specific search space.

A UE is not required to simultaneously monitor a NPDCCH UE-specificsearch space and a Type-1-NPDCCH common search space.

A UE is not required to simultaneously monitor a NPDCCH UE-specificsearch space and a Type2-NPDCCH common search space.

A UE is not required to simultaneously monitor a Type-1-NPDCCH commonsearch space and a Type2-NPDCCH common search space.

An NPDCCH search space NS_(k) ^((L′R)) at aggregation level L′∈{1,2} andrepetition level R∈{1,2,4,8,16,32,64,128,256,512,1024,2048} is definedby a set of NPDCCH candidates where each candidate is repeated in a setof R consecutive NB-IoT downlink subframes excluding subframes used fortransmission of SI messages starting with subframe k.

For NPDCCH UE-specific search space, the aggregation and repetitionlevels defining the search spaces and the corresponding NPDCCHcandidates are listed in Table 16.6-1 in FIG. 12 by substituting thevalue of R_(max) with the higher layer configured parameteral-Repetition-USS.

For Type1-NPDCCH common search space, the aggregation and repetitionlevels defining the search spaces are listed in Table 16.6-2 in FIG. 13by substituting the value of R_(max) with the higher layer configuredparameter al-Repetition-CSS-Paging.

For Type2-NPDCCH common search space, the aggregation and repetitionlevels defining the search spaces and the corresponding monitored NPDCCHcandidates are listed in Table 16.6-3 in FIG. 14 by substituting thevalue of R_(max) with the higher layer configured parameternpdcch-MaxNumRepetitions-RA.

The locations of starting subframe are given by k=k_(b) where K_(b) isthe th consecutive NB-IoT DL subframe from subframe, and b=u·R, and

${u = 0},1,\ldots \mspace{14mu},{\frac{R_{\max}}{R} - 1},$

and where

-   -   subframe is a subframe satisfying the condition        (10n_(f)+└n_(s)/2┘)mod T=α_(offset)·T, where T=R_(max)·G    -   for NPDCCH UE-specific search space,    -   G is given by the higher layer parameter nPDCCH-startSF-UESS,    -   α_(offset) is given by the higher layer parameter        nPDCCH-startSFoffset-UESS,    -   for NPDCCH Type2-NPDCCH common search space,    -   G given by the higher layer parameter nPDCCH-startSF-Type2CSS,        is    -   α_(offset) is given by the higher layer parameter        nPDCCH-startSFoffset-Type2CSS,

For Type1-NPDCCH common search space, k=k0 and is determined fromlocations of NB-IoT paging opportunity subframes.

If the UE is configured by high layers with a PRB for monitoring ofNPDCCH UE-specific search space,

-   -   the UE shall monitor the NPDCCH UE-specific search space on the        higher layer configured PRB,    -   the UE is not expected to receive NPSS, NSSS, NPBCH on the        higher layer configured PRB.

otherwise,

-   -   the UE shall monitor the NPDCCH UE-specific search space on the        same PRB on which NPSS/NSSS/NPBCH are detected.

If a NB-IoT UE detects NPDCCH with DCI Format NO ending in subframe n,and if the corresponding NPUSCH format 1 transmission starts from n+k,the UE is not required to monitor NPDCCH in any subframe starting fromsubframe n+1 to subframe n+k−1.

If a NB-IoT UE detects NPDCCH with DCI Format N1 or N2 ending insubframe n, and if the corresponding NPDSCH transmission starts fromn+k, the UE is not required to monitor NPDCCH in any subframe startingfrom subframe n+1 to subframe n+k−1.

If a NB-IoT UE detects NPDCCH with DCI Format N1 ending in subframe n,and if the corresponding NPUSCH format 2 transmission starts fromsubframe n+k, the UE is not required to monitor NPDCCH in any subframestarting from subframe n+1 to subframe n+k−1.

If a NB-IoT UE detects NPDCCH with DCI Format N1 for “PDCCH order”ending in subframe n, and if the corresponding NPRACH transmissionstarts from subframe n+k, the UE is not required to monitor NPDCCH inany subframe starting from subframe n+1 to subframe n+k−1.

If a NB-IoT UE has a NPUSCH transmission ending in subframe n, the UE isnot required to monitor NPDCCH in any subframe starting from subframen+1 to subframe n+3.

A NB-IoT UE is not required to monitor NPDCCH candidates of an NPDCCHsearch space if an NPDCCH candidate of the NPDCCH search space ends insubframe n, and if the UE is configured to monitor NPDCCH candidates ofanother NPDCCH search space starting before subframe n+5.

The present disclosure proposes a method of configuring an NPDCCH searchspace or an MPDCCH search space for supporting SC-PTM of a BL/CEterminal and an NB-IoT teminal.

Particularly, the present disclosure proposes a method of defining asearch space for transmitting a NPDCCH or an MPDCCH. Herein, the searchspace is configured with MPDCCH candidates or NPDCCH candidates, and theNPDCCH or the MPDCCH is i) CRC-scrambled based on an SC-RNTI fortransmitting PDSCH scheduling information for transmission of SC-MCCHinformation for transmission of SC-PTM related control information, orii) CRC-scrambled based on an SC-N-RNTI that notifies of a change of anSC-MCCH.

According to a method of transmitting SC-MCCH information for a typicalLTE terminal, a SC-PTM service applied LTE terminal can acquirescheduling information for a PDSCH that transmits an SC-MCCH, byreceiving DCI CRC-scrambled based on an SC-RNTI and an SC-N-RNTI througha CSS of the PDCCH. However, in a case of a BL/CE terminal and an NB-IoTterminal, reception of the corresponding PDCCH is not possible.

Therefore, when the SC-PTM is supported for a BL/CE terminal and anNB-IoT terminal, it is necessary to separately configure an MPDCCHsearch space and an NPDCCH search space for enabling the BL/CE terminaland the NB-IoT terminal to receive DCI for transmission of schedulinginformation for the PDSCH that transmits the SC-MCCH.

The present disclosure proposes a method of configuring an MPDCCH searchspace and an NPDCCH search space for enabling a BL/CE terminal and anNB-IoT terminal to receive scheduling information for a PDSCH includingan SC-MCCH.

Method 1. A Method of Transmitting SC-MCCH Scheduling ControlInformation Through a Type-1 Common Search Space (CSS)

It may be defined as follows: a base station/cell/TRP i) performsCRC-scrambling on DCI including scheduling information for an SC-MCCHfor providing an SC-PTM service and DCI including notificationinformation for a change of the SC-MCCH, by using an SC-RNTI and anSC-N-RNTI, respectively, and ii) transmits the CRC-scrambled DCI throughthe type-1 common search space including MPDCCH candidates or NPDCCHcandidates, which is for transmitting DCI including schedulinginformation for a paging message for BL/CE terminals and NB-IoTterminals.

In this case, it may be defined that the SC-PTM service appliedBL/CE/NB-IoT terminals perform blind decoding for the MPDCCH candidatesor the NPDCCH candidates constituting the type-1 CSS defined for thecorresponding terminal, based on the the SC-RNTI and the SC-N-RNTI aswell as a P-RNTI.

That is, in a case of DCI including PDSCH scheduling control informationfor the SC-MCCH, the DCI may be CRC-scrambled based on the SC-RNTI andtransmitted through the NPDCCH or the MPDCCH of the corresponding type-1CSS, and each of the BL/CE terminal and the NB-IoT terminal may receivescheduling control information for the corresponding SC-MCCH bymonitoring the type-1 CSS.

Also, the 8-bit bitmap information for notification of the change of theSC-MCCH is CRC-scrambled based on the SC-N-RNTI and transmitted throughthe NPDCCH or the MPDCCH of the corresponding type-1 CSS. Each of theBL/CE terminal and the NB-IoT terminal may receive the notification ofthe change of the SC-MCCH by monitoring the type-1 CSS.

However, when scheduling control information for the SC-RNTI-basedSC-MCCH is transmitted through the type-1 CSS, it may be defined to usea DCI format defined for paging (that is, DCI format 6-2 in a case ofthe BL/CE terminal, and DCI format N2 in a case of the NB-IoT termimal)in the same way, as a DCI format for the transmission of the schedulingcontrol information for the SC-RNTI-based SC-MCCH.

Alternatively, when scheduling control information for the SC-RNTI-basedSC-MCCH is transmitted through the type-1 CSS, it may be defined to usea DCI format different from the DCI format defined for paging. Forexample, it may be defined to transmit the MPDCCH scrambled by acorresponding SC-RNTI based on DCI format 6-1A or DCI format 6-1B in acase of the BL/CE terminal, and to transmit the NPDCCH scrambled by acorresponding SC-RNTI based on DCI format N1 in a case of the NB-IoTterminal.

Likewise, even in a case where the MPDCCH or the NPDCCH, that isCRC-scrambled based on the SC-N-RNTI and transmitted in order to notifyof a change of the SC-MCCH through the type-1 CSS, it may be defined touse the DCI format defined for paging (that is, DCI format 6-2 in a caseof the BL/CE terminal, and DCI format N2 in a case of the NB-IoTtermimal) in the same way.

Alternatively, when notification information for the change of theSC-RNTI-based SC-MCCH is transmitted through the type-1 CSS, it may bedefined to use a DCI format different from the DCI format defined forpaging. For example, it may be defined to transmit the MPDCCH scrambledby a corresponding SC-RNTI based on DCI format 6-1A or DCI format 6-1Bin a case of the BL/CE terminal, and to transmit the NPDCCH scrambled bya corresponding SC-RNTI based on DCI format N1 in a case of the NB-IoTterminal.

Method 2. A Method of Defining a Separate CSS

A type-3 CSS, an SC-SS, or a group search space (GSS) for transmittingDCI including scheduling control information for an SC-MCCH may befurther defined in addition to a type-0 CSS, a type-1 CSS, a type-2 CSS,and a USS, which are defined for the BL/CE terminal and the NB-IoTterminal.

In this case, RRC parameters for configuring the type-3 CSS (or SC-SS orGSS) may be transmitted through cell-specific RRC signaling.

Hereinafter, a method of configuring a separate CSS (or SC-SS or GSS)for the NB-IoT terminal according to an embodiment will be described.

In a case of a type-3 NB-IoT terminal, a corresponding type-3 CSS (SC-SSor GSS) may be configured by i) separately defining: a parameter forconfiguring a value of a maximum number of repetition transmission timesof NPDCCH, npdcch-MaxNumRepetitions-SCPTM; a G value configurationparameter for defining a start subframe, nPDCCH-startSF-Type3CSS; and anα_(offset) value configuration parameter, nPDCCH-startSFoffset-Type3CSS,ii) transmitting the defined parameters through UE-specific RRCsignaling or cell-specific RRC signaling, and iii) applying thetransmitted parameters to an existing NPDCCH search space configurationexpression.

Alternatively, the corresponding type-3 CSS (SC-SS or GSS) may beconfigured by i) applying, as a value of a maximum number of repetitiontransmission times of NPDCCH, an RRC parameter value configured forpaging, al-Repetition-CSS-Paging; ii) separately defining a G valueconfiguration parameter for defining a start subframe,nPDCCH-startSF-Type3CSS, and an α_(offset) value configurationparameter, nPDCCH-startSFoffset-Type3CSS; iii) transmitting theparameters through UE-specific RRC signaling or cell-specific RRCsignaling; and iv) applying the parameters to an existing NPDCCH searchspace configuration expression.

Alternatively, it may be defined i) to separately define a parameter forconfiguring a value of a maximum number of repetition transmission timesof NPDCCH, npdcch-MaxNumRepetitions-SCPTM, for configuring the type-3CSS (SC-SS or GSS) and transmit them through UE-specific RRC signalingor cell-specific RRC signaling, and ii) to determine a subframeconstituting the corresponding type-3 CSS (SC-SS or GSS) by an RRCparameter for the SC-PTM configuration, which includessc-mcch-RepetionPeriod-r13, sc-mcch-Offset-r13,sc-mcch-FirstSubframe-r13, sc-mcch-duration-r13, andsc-mcch-ModificationPeriod-r13.

Alternatively, it may be defined i) to apply an RRC parameter valueconfigured for paging, al-Repetition-CSS-Paging, as a value of a maximumnumber of repetition transmission times of NPDCCH, for configuring thetype-3 CSS (SC-SS or GSS), and ii) to determine a subframe constitutingthe type-3 CSS (SC-SS or GSS) by RRC parameters for the SC-PTMconfiguration, which includes sc-mcch-RepetionPeriod-r13,sc-mcch-Offset-r13, sc-mcch-FirstSubframe-r13, sc-mcch-duration-r13, andsc-mcch-ModificationPeriod-r13.

Hereinafter, a method of configuring a separate CSS (or SC-SS or GSS)for the BL/CE terminal according to an embodiment will be described.

As another method of defining a separate type-3 CSS, an SC-SS, or agroup search space (GSS), in a case of the BL/CE terminal, allocationinformation of a PRB constituting an MPDCCH set for configuring thetype-3 CSS (or SC-SS or GSS) may be transmitted through UE-specific RRCsignaling or cell-specific RRC signaling.

In addition, the type-3 CSS (or an SC-SS or GSS) may be furtherconfigured by i) separately defining a parameter for configuring a valueof a maximum number of repetition transmission times of MPDCCH,mPDCCH-NumRepetition-SCPTM, and a G value configuration parameter fordefining a start subframe, mPDCCH-startSF-CSS-SCPTM, and ii)transmitting the defined parameters through UE-specific RRC signaling orcell-specific RRC signaling.

Alternatively, the type-3 CSS (or an SC-SS or GSS) may be configured by:i) applying, as a value of a maximum number of repetition transmissiontimes of MPDCCH, an RRC parameter value configured for paging,mPDCCH-NumRepetition-Paging; ii) separately defining only a G valueconfiguration parameter for defining a start subframe,mPDCCH-startSF-CSS-SCPTM; and iii) transmitting the parameters throughUE-specific RRC signaling or cell-specific RRC signaling.

Alternatively, it may be defined i) to separately define a parameter forconfiguring a value of a maximum number of repetition transmission timesof MPDCCH, mPDCCH-NumRepetition-SCPTM, and ii) to transmit the definedparameter through UE-specific RRC signaling or cell-specific RRCsignaling, and iii) to determine a subframe constituting thecorresponding type-3 CSS (or an SC-SS or GSS) by an RRC parameter forthe SC-PTM configuration, which includes sc-mcch-RepetionPeriod-r13,sc-mcch-Offset-r13, sc-mcch-FirstSubframe-r13, sc-mcch-duration-r13, andsc-mcch-ModificationPeriod-r13.

Alternatively, it may be defined i) to apply an RRC parameter valueconfigured for paging, mPDCCH-NumRepetition-Paging, as a value of amaximum number of repetition transmission times of MPDCCH, forconfiguring the corresponding type-3 CSS (or an SC-SS or GSS), and ii)to determine a subframe constituting the type-3 CSS (or an SC-SS or GSS)by an RRC parameter for the SC-PTM configuration, which includessc-mcch-RepetionPeriod-r13, sc-mcch-Offset-r13,sc-mcch-FirstSubframe-r13, sc-mcch-duration-r13, andsc-mcch-ModificationPeriod-r13.

Further, it may be defined to apply an MPDCCH transmission mode of adistributed type to an MPDCCH set for configuring the correspondingtype-3 CSS (or an SC-SS or GSS).

Further, the present disclosure proposes a method of configuring anMPDCCH search space or an NPDCCH search space for transmitting orreceiving allocation information for a PDSCH including an SC-MCCH thatis a multicasting control channel. However, the method may be applied,in the same way, to configuration of a search space for transmitting anSC-MTCH that is a multicasting data channel, by replacing the SC-RNTI orthe SC-N-RNTI with a G-RNTI.

FIG. 15 and FIG. 16 are diagrams illustrating a method of transmittingor receiving a multicasting control channel for an NB-IoT terminal. FIG.15 shows a method of receiving a multicasting control channel by anNB-IoT terminal, and FIG. 16 shows a method of transmitting amulticasting control channel for an NB-IoT terminal by a base station.

Referring to FIG. 15, an NB-IoT terminal receives configurationinformation relating to an NPDCCH search space that is separatelyconfigured to receive scheduling control information for a multicastingcontrol channel from a base station at step S1500.

As described, the NPDCCH search space is separately configured toreceive scheduling control information for the multicasting controlchannel. Such a NPDCCH search space may be a search space definedseparately in addition to predefined search spaces.

That is, the NPDCCH search space may be a search space definedadditionally and separately from the type-1 common search space forpaging, the type-2 common search space for a random access procedure,and a UE-specific search space for transmitting or receiving UE-specificdata, which are defined as NPDCCH search spaces.

The configuration information relating to the separately configuredNPDCCH search space may include a maximum number of repetitiontransmission times of the NPDCCH, a start subframe configurationparameter, and an offset parameter, which are for configuring the NPDCCHsearch space.

The configuration information associated to this NPDCCH search space maybe received through higher layer signaling.

The NB-IoT terminal receives, from the base station, scheduling controlinformation for a multicasting control channel through the NPDCCH searchspace configured based on the received configuration information at stepS1510.

The NB-IoT terminal checks a resource for multicasting control channeltransmission and receives a multicasting control channel, based onscheduling control information received through the separately definedNPDCCH search space at step S1520.

Referring to FIG. 16, a base station configures a separate NPDCCH searchspace for transmitting scheduling control information for a multicastingcontrol channel for an NB-IoT terminal at step S1600.

The separately configured NPDCCH search space may be a search spaceseparately defined for transmission or reception of scheduling controlinformation for the multicasting control channel in addition to a type-1common search space, a type-2 common search space, and a UE-specificsearch space, which are predefined NPDCCH search spaces.

The base station transmits configuration information of the separatelydefined NPDCCH search space to the NB-IoT, and transmits schedulingcontrol information for the multicasting control channel through theNPDCCH search space at step S1610.

Here, the base station may transmit the configuration informationrelating to the separately defined NPDCCH search space through higherlayer signaling.

Further, the configuration information associated to the separatelydefined NPDCCH search space may include a maximum number of repetitiontransmission times of NPDCCH and a start subframe configurationparameter, and an offset parameter, which are for configuring the NPDCCHsearch space.

The base station transmits the multicasting control channel based onscheduling control information transmitted through the separatelydefined NPDCCH search space to the NB-IoT terminal at step S1620.

Therefore, according to the present embodiments, a multicasting controlchannel for an NB-IoT terminal may be transmitted or received byconfiguring an NPDCCH search space separately configured in addition topredefined NPDCCH search spaces, and transmitting or receivingscheduling control information for the multicasting control channelthrough the separately defined NPDCCH search space.

FIG. 17 and FIG. 18 are diagrams illustrating a method for transmittingor receiving a multicasting control channel for a BL/CE terminalaccording to the present embodiments. FIG. 17 shows a method ofreceiving a multicasting control channel by a BL/CE terminal, and FIG.18 shows a method of transmitting a multicasting control channel for aBL/CE terminal by a base station.

Referring to FIG. 17, a BL/CE terminal receives configurationinformation relating to an MPDCCH search space separately configured toreceive scheduling control information for a multicasting controlchannel from a base station at step S1700.

Here, the MPDCCH search space separately configured to receivescheduling control information for the multicasting control channel maybe a search space defined additionally and separately from predefinedMPDCCH search spaces.

That is, the separately configured MPDCCH search space may be a searchspace defined additionally and separately a search space defined toperform monitoring only when the BL/CE terminal is configured withCEModeA, a search space for paging, a search space for a random accessprocedure, and a search space for transmitting or receiving UE-specificdata.

The configuration information relating to the MPDCCH search spacereceived from the base station may include a maximum number ofrepetition transmission times of MPDCCH and a start subframeconfiguration parameter, which are for configuring the MPDCCH searchspace.

Further, the configuration information relating to the separatelyconfigured MPDCCH search space may be received through higher layersignaling.

The BL/CE terminal receives scheduling control information for themulticasting control channel through the separately configured MPDCCHsearch space S1710. Here, the MPDCCH that transmits scheduling controlinformation for the multicasting control channel may be transmitted in adistributed type.

The BL/CE terminal receives the multicasting control channel transmittedbased on the scheduling control information at step S1720.

Referring to FIG. 18, a base station configures a separate MPDCCH searchspace for transmitting scheduling control information for a multicastingcontrol channel for a BL/CE terminal at step S1800.

The separately configured MPDCCH search space may be a search spacedefined additionally and separately from predefined MPDCCH searchspaces. That is, the separately configured MPDCCH search space may be asearch space defined additionally and separately from a search spacedefined to perform monitoring only when the BL/CE terminal is configuredwith CEModeA, a search space for paging, a search space for arandom-access procedure, and a UE-specific search space.

The base station transmits configuration information relating to theseparately configured MPDCCH search space, and transmits schedulingcontrol information for the multicasting control channel through theseparately configured MPDCCH search space, to the terminal at stepS1810.

The configuration information relating to the separately configuredMPDCCH search space may include a maximum number of repetitiontransmission times of MPDCCH and a start subframe configurationparameter, which are for configuring the MPDCCH search space, and may betransmitted through higher layer signaling.

Further, the MPDCCH that transmits scheduling control information forthe multicasting control channel may be transmitted in a distributedtype.

The base station transmits the multicasting control channel based onscheduling control information transmitted through the separatelyconfigured MPDCCH search space at step S1820.

Therefore, according to present embodiments, transmission or receptionof a multicasting control channel for a BL/CE terminal may be performedby additionally defining an MPDCCH search space in addition topredefined MPDCCH search spaces and transmitting scheduling controlinformation for the multicasting control channel through theadditionally defined MPDCCH search space.

FIG. 19 is a diagram illustrating a configuration of a user equipment1900 according to the present embodiments.

Referring to FIG. 19, the user equipment 1900 according to the presentembodiments includes a reception unit 1910, a control unit 1920, and atransmission unit 1930.

The reception unit 1910 receives downlink control information, data, anda message through a corresponding channel from a base station.

Further, according to the present disclosure described above, thecontrol unit 1920 configures a search space for transmitting orreceiving scheduling control information for a multicasting controlchannel for an MTC terminal and an NB-IoT terminal, and controls anoverall operation of the user equipment 1900 based on to transmission orreception of the multicasting control channel.

The transmission unit 1930 transmits uplink control information, data,and a message through a corresponding channel to the base station.

FIG. 20 is a diagram illustrating a configuration of a base station 2000according to the present embodiments.

Referring to FIG. 20, the base station 2000 according to the presentembodiments includes a control unit 2010, a transmission unit 2020, anda reception unit 2030.

According to the present disclosure described above, the control unit2010 configures a search space for transmitting or receiving schedulingcontrol information for a multicasting control channel for an MTCterminal and an NB-IoT terminal, and controls an overall operation ofthe base station 2000 based on based on transmission or reception of themulticasting control channel.

The transmission unit 2020 and the reception unit 2030 are used fortransmitting or receiving a signal, a message, and data necessary forperforming the aforementioned present disclosure to or from theterminal.

The standard details or standard documents mentioned in the aboveembodiments are omitted for the simplicity of the description of thespecification, and constitute a part of the present specification.Therefore, when a part of the contents of the standard details and thestandard documents is added to the present specifications or isdisclosed in the claims, it should be construed as falling within thescope of the present disclosure.

Although a preferred embodiment of the present disclosure has beendescribed for illustrative purposes, those skilled in the art willappreciate that various modifications, additions and substitutions arepossible, without departing from the scope and spirit of the todisclosure as disclosed in the accompanying claims. Therefore, exemplaryaspects of the present disclosure have not been described for limitingpurposes. The scope of the present disclosure shall be construed basedon the accompanying claims in such a manner that all of the technicalideas included within the scope equivalent to the claims belong to thepresent disclosure.

1-12. (canceled)
 13. A method of receiving a multicasting controlchannel (SC-MCCH) by a NarrowBand-Internet of Things (NB-IoT) terminal,the method comprising: receiving configuration information relating toan narrowband physical downlink control channel (NPDCCH) search spacefrom a base station wherein the NPDCCH search space is separatelyconfigured to receive scheduling control information for themulticasting control channel; receiving the scheduling controlinformation for the multicasting control channel through the NPDCCHsearch space configured based on the configuration information; andreceiving the multicasting control channel based on the schedulingcontrol information, wherein the configuration information is receivedthrough higher layer signaling, and wherein the configurationinformation includes a maximum number of repetition transmission timesof NPDCCH, a start subframe configuration parameter for defining a startsubframe for the NPDCCH search space, and an offset parameter fordefining an offset for the NPDCCH search space, which are forconfiguring the NPDCCH search space, and wherein the NPDCCH search spaceis a search space configured separately from a search space predefinedfor paging of the NB-IoT terminal.
 14. The method of claim 13, whereinthe NB-IoT terminal performs blind decoding of the NPDCCH based on themaximum number of repetition transmission times of the NPDCCH, the startsubframe configuration parameter, and the offset parameter.
 15. A methodof transmitting a multicasting control channel for anNarrowBand-Internet of Things (NB-IoT) terminal, the method comprising:configuring a separate narrowband physical downlink control channel(NPDCCH) search space for transmitting scheduling control informationfor the multicasting control channel; transmitting the schedulingcontrol information for the multicasting control channel through theNPDCCH search space; and transmitting the multicasting control channelbased on the scheduling control information, wherein the configurationinformation relating to the NPDCCH search space is transmitted throughhigher layer signaling, and wherein the configuration informationincludes a maximum number of repetition transmission times of NPDCCH, astart subframe configuration parameter for defining a start subframe forthe NPDCCH search space, and an offset parameter for defining an offsetfor the NPDCCH search space, which are for configuring the NPDCCH searchspace, and wherein the NPDCCH search space is a search space configuredseparately from a search space predefined for paging, a search space fora random access procedure, and a UE-specific search space fortransmitting or receiving UE-specific data of the NB-IoT terminal. 16.The method of claim 15, wherein blind decoding of the NPDCCH isperformed based on the maximum number of repetition transmission timesof the NPDCCH, the start configuration parameter, and the offsetparameter by the NB-IoT terminal.
 17. An NarrowBand-Internet of Things(NB-IoT) terminal configured to receive a multicasting control channel,the NB-IoT terminal comprising: a reception unit configured to receiveconfiguration information relating to an narrowband physical downlinkcontrol channel (NPDCCH) search space from a base station, wherein theNPDCCH search space is separately configured to receive schedulingcontrol information for the multicasting control channel; and a controlunit configured to check the scheduling control information for themulticasting control channel through the NPDCCH search space configuredbased on the configuration information, and control reception of themulticasting control channel based on the scheduling controlinformation, wherein the configuration information is received throughhigher layer signaling, wherein the configuration information includes amaximum number of repetition transmission times of NPDCCH, a startsubframe configuration parameter for defining a start subframe for theNPDCCH search space, and an offset parameter for defining an offset forthe NPDCCH search space, which are for configuring the NPDCCH searchspace, and wherein the NPDCCH search space is a search space configuredseparately from a search space predefined for paging, a search space fora random access procedure, and a UE-specific search space fortransmitting or receiving UE-specific data of the NB-IoT terminal. 18.The NB-IoT terminal of claim 17, wherein blind decoding of the NPDCCH isperformed based on the maximum number of repetition transmission timesof the NPDCCH, the start configuration parameter, and the offsetparameter by the NB-IoT terminal.
 19. A base station configured totransmit a multicasting control channel for an NarrowBand-Internet ofThings (NB-IoT) terminal, the base station comprising: a control unitconfigured to configure a separate narrowband physical downlink controlchannel (NPDCCH) search space for transmitting scheduling controlinformation for the multicasting control channel, and controltransmission of the scheduling control information for the multicastingcontrol channel through the NPDCCH search space; and a transmission unitconfigured to transmit the multicasting control channel based on thescheduling control information, wherein the configuration informationrelating to the NPDCCH search space is transmitted through higher layersignaling, and wherein the configuration information includes a maximumnumber of repetition transmission times of NPDCCH, a start subframeconfiguration parameter for defining a start subframe for the NPDCCHsearch space, and an offset parameter for defining an offset for theNPDCCH search space, which are for configuring the NPDCCH search space,and wherein the NPDCCH search space is a search space configuredseparately from a search space predefined for paging, a search space fora random access procedure, and a UE-specific search space fortransmitting or receiving UE-specific data of the NB-IoT terminal. 20.The base station of claim 19, wherein the NB-IoT terminal performs blinddecoding of the NPDCCH based on the maximum number of repetitiontransmission times of the NPDCCH, the start subframe configurationparameter, and the offset parameter.